Column-type machine tool

ABSTRACT

A column-type machining arrangement for machining a workpiece is provided, including a machine bed; a traversable column slidably coupled to the machine bed; a tool carrier coupled to the column, the tool carrier configured to detachably couple to a tool for machining the workpiece; a plurality guideways to guide the traversable column on the machine bed, the guideways including a first guideway arranged on the machine bed below the column and a second guideway arranged centrally and laterally next to the column at a height equal to approximately half a height of the column; and a first drive arrangement configured to cause the column to slidably traverse on the machine bed, the first drive arrangement acting on the column at a level of the second guideway.

[0001] The invention relates to a column-type machine tool, in particular a milling center, having a traversable column and a tool carrier arranged thereon.

[0002] Such a column-type machine tool is described in DE 196 45 324 A1, having a machine bed, a column which is traversable on the machine bed on guideways and on which at least one cutting tool movable in several axes is arranged, a supporting structure with guideways for the top end of the column, and at least one traverse drive, interacting with the guideways of the machine bed and of the supporting structure, for the column.

[0003] If there is only one traverse drive in this machine tool, no sufficiently high accelerations can be achieved during the traverse of the column, since this traverse drive acts well away from the center of gravity of the column and therefore produces a tilting moment during acceleration. Although this disadvantage is avoided by synchronous traverse drives in the region of the bottom and the top guideway on the column, the outlay for the traverse drives is doubled. The supporting structure is also complicated, since it has to be approximately just as high as the column in order to be able to arrange a guideway in the region of the top end of the column.

[0004] These problems also occur in the column-type machine tool described in DE 28 52 846 C2, the column of which is guided solely in guideways in the base region on the machine bed.

[0005] The problem underlying the invention is to provide a column-type machine tool which, in a simple construction and with the lowest possible masses to be moved, ensures accurate guidance at high accelerations and decelerations in order to thereby increase the stock-removing capacity and the machining accuracy. In addition, the chip disposal is to be improved.

[0006] Starting from this problem, in the case of a column-type machine tool of the type mentioned at the beginning, it is proposed that, according to the invention, a guideway be arranged below the column on the machine bed, that a further guideway be arranged laterally next to the column, approximately centrally at half the height of the column, and that a traverse drive act on the column at the level of the lateral guideway.

[0007] Since the guideway arranged laterally next to the column approximately at half the height of the column lies approximately at the level of the center of gravity of the column, no tilting moment can act on the column by the traverse drive during acceleration and deceleration, and therefore the column cannot tilt on the guideways. Thus, with only one traverse drive, high acceleration and deceleration rates are possible without having to provide a second traverse drive, with the complications associated therewith.

[0008] Even if a perpendicularly traversable tool carrier is arranged on the column, the aforesaid advantages are retained, even when the tool carrier is located in its lowermost or topmost position on the column, since the mass of the tool carrier can be kept small in relation to the column and the maximum distance from the center of gravity can at most be only equal to half the column height.

[0009] The tool carrier can be designed as a universal tool carrier for mounting a turning tool, preferably in a tool slide traversable parallel to the guideways, or as a headstock with horizontal work spindle which is arranged thereon and preferably runs parallel to the guideways of the column.

[0010] The work spindle may be arranged so as to be axially traversable in the tool carrier.

[0011] A work table which is traversable on guideways transversely to the guideways of the column and can preferably be rotatable may be arranged in front of the column, so that the work table can perform a feed movement in the X-axis, the tool carrier can perform a feed movement in the Y-axis and the column can perform a feed movement in the Z-axis.

[0012] The chip disposal can be improved with the arrangement according to the invention, since covers running at an angle of 45° can be arranged in the region of the guideways on the machine bed. These covers direct chips thrown against them into a chip trough below the tool carrier, the chips being removed therefrom by means of a chip conveyor.

[0013] Roof-shaped telescopic covers may be arranged over the guideways adjacent to the column for the work table, and sloping telescopic covers, through which the chips are directed into chip troughs arranged on both sides of the roof-shaped telescopic cover, may be arranged over the guideways remote from the column for the work table.

[0014] The chips are removed from these chip troughs by chip conveyors, in the course of which the chip conveyor in the chip trough at the column conveys into the chip trough adjacent to the roof-shaped telescopic covers.

[0015] The invention is explained in more detail below with reference to an exemplary embodiment shown in the drawing.

[0016] In the drawing:

[0017]FIG. 1 shows a perspective view of the column-type machine tool according to the invention with removed covers, and

[0018]FIG. 2 shows a perspective view of the column-type machine tool according to the invention from another angle with covers shown on the guideways.

[0019] A machine bed designated in general by the designation 1 consists of a horizontal base plate 13 and an approximately perpendicular plate 14 which is arranged thereon and forms a supporting structure.

[0020] A column 2 is guided by means of a guideway 6 on an edge of the base plate 13 and approximately at half the height by means of a guideway 5 on the top edge of the perpendicular plate 14. The bottom guideway 6 is arranged below the column 2 approximately in its perpendicular center-of-gravity plane, whereas the top, lateral guideway 5 lies approximately at half the height of the column 2.

[0021] On the column 2, a tool carrier 3 is perpendicularly traversable on guideways 8 by means of a traverse drive 17. In the exemplary embodiment shown, the tool carrier 3 is designed as a headstock and carries a work spindle 4, which if need be can be designed to be axially traversable in the tool carrier 3.

[0022] The work spindle 4 may be designed for mounting milling cutters or angular milling heads. Likewise, a face plate can be attached to the work spindle 4. Finally, the work spindle 4 may also be designed as a tool slide for mounting a turning tool if a workpiece is to be machined on the rotary table 9 arranged in front of it in the manner of a vertical lathe.

[0023] A traverse drive 7 engages on the column 2 at the level of the top guideway 5, so that high acceleration and deceleration rates can be achieved without a substantial tilting moment acting on the column.

[0024] By means of guideways 11, 12, the rotary table 9 is traversable on a bed 10 transversely to the direction of movement of the column 2. A traverse drive 16 is provided for this purpose. A rotary drive 15 serves to rotate the rotary table 9, either for the angular positioning of a workpiece on the rotary table 9 or as a rotary drive for the rotary table 9 if a workpiece arranged thereon is to be machined in a rotary manner by means of a turning tool.

[0025] A top, sloping telescopic cover 18 for the top guideway 5, a sloping, fixed cover plate 19 and a bottom, sloping telescopic cover 20 for the bottom guideway 6 can be seen in FIG. 2. Chips thrown against the covers 18, 19, 20 during the machining of a workpiece are directed into a chip trough 21 below a tool carrier. A flat telescopic cover 20 protects the guideways 8 on the column 2 from contamination by chips.

[0026] Roof-shaped telescopic covers 23 are arranged over the guideway 11 for the rotary table 9 on both sides of the latter, whereas sloping telescopic covers 24 are sufficient for the guideway 12.

[0027] A chip trough 25 is formed on that side of the roof-shaped telescopic covers 23 which faces the column 2, whereas a further chip trough 26 is formed between the roof-shaped telescopic covers 23 and the sloping telescopic covers 24. The chips in these chip troughs 25, 26 are removed by chip conveyors 27, 28. The chips in the chip trough 21 are transported into the chip trough 25 by means of a chip conveyor (not shown) and are removed therefrom, as already mentioned, by the chip conveyor 27. 

1. A column-type machine tool, in particular a milling center, having a traversable column (2) and a tool carrier (3) arranged thereon, a machine bed (1), guideways (5, 6) for the column (2) traversable on the machine bed (1), of which guideways (5, 6) one guideway (6) is arranged below the column (2) on the machine bed (1), a further guideway (5) is arranged laterally next to the column (2), approximately centrally at half the height of the column (2), and having a traverse drive (7) which acts on the column (2) at the level of the lateral guideway (5).
 2. The column-type machine tool as claimed in claim 1, having a machine bed (1) consisting of a horizontal plate (13), with the guideway (6) running along a lateral edge, and of an approximately perpendicular plate (14) which rises thereon, forms a supporting structure and has the guideway (5) on the top edge.
 3. The column-type machine tool as claimed in claim 1 or 2, having a tool carrier (3) perpendicularly traversable on the column (2).
 4. The column-type machine tool as claimed in claim 3, having a tool carrier (3) designed for mounting a turning tool.
 5. The column-type machine tool as claimed in claim 4, having a tool slide which is traversable parallel to the guideways (5, 6) and is intended for mounting the turning tool.
 6. The column-type machine tool as claimed in claim 1, 2 or 3, having a tool carrier (3) designed as a headstock.
 7. The column-type machine tool as claimed in claim 6, having a horizontal work spindle (4) arranged on the headstock (3).
 8. The column-type machine tool as claimed in claim 7, having a work spindle axis running parallel to the guideways (5, 6).
 9. The column-type machine tool as claimed in claim 6, 7 or 8, having an axially traversable work spindle (4).
 10. The column-type machine tool as claimed in one of claims 1 to 9, having a work table (9) which is traversable on guideways (11, 12) transversely to the guideways (5, 6) of the column (2).
 11. The column-type machine tool as claimed in claim 10, having a rotatable work table (9).
 12. The column-type machine tool as claimed in one of claims 1 to 11, having covers (18, 19, 20) in the region of the guideways (5, 6) on the machine bed (1), said covers (18, 19, 20) sloping at an angle of at least 45° and directing chips thrown against them into a chip trough (21) below the tool carrier (3), and having a chip conveyor in the chip trough (21).
 13. The column-type machine tool as claimed in claim 10, 11 or 12, having roof-shaped telescopic covers (23) over guideways (11) adjacent to the column (2) for the work table (9) and having a sloping telescopic cover (24) over guideways (12) remote from the column (2) for the work table (9), and having chip troughs (25, 26) with chip conveyors (27, 28) on both sides of the roof-shaped telescopic cover (23).
 14. The column-type machine tool as claimed in claim 13, in which the chip conveyor in the chip trough (21) at the column (2) conveys into the chip trough (25) adjacent to the roof-shaped telescopic covers (23). 